Recent advances in semiconductor technology have made the determination of the concentration of an element at the surface, or near surface, e.g., within a few tens of angstroms of the surface, a significant issue. For example, development of ultra-shallow devices requires a quantitative method for providing information starting at the surface of the material. Moreover, the concentration of desired elements, e.g., dopants, and undesired elements, e.g., contaminants, are of importance.
Unfortunately, elemental measurement at surface or near surface conditions is complicated by the lack of reliable reference standards for these measurements.
In the past, the art has employed certain chemical preparations in an attempt to facilitate the determination of the concentration at the surface of the material. One example of such a technique has involved dissolving a powder in a liquid and applying the solution over the surface to be tested in such a manner so as to leave a residue of the powder on the surface to be tested. However, these chemical preparations have proven less than satisfactory. For example, such techniques are difficult to reproduce and non-uniform in character, thus, they have not been effective in providing a consistent result.
Thus the need still exists for a method of preparing, and in particular calibrating, a surface which will facilitate surface or near surface elemental measurements thereof